1. Field of the Invention
The invention relates to a method of making a recess termination in a component. In this case, the termination of the recess is to be designed in such a way that the latter does not continue to grow despite loading of the component.
2. Discussion of Background
In the construction of machines and apparatus there is often the problem of preventing further growth of a crack which has grown on account of excessive loading or of eliminating crack growth due to the notch effect at the end of a relief slot specifically made in a wall of a component. A known method of the prior art for solving this problem consists in "boring out" the recess, by a hole of sufficiently large bore diameter being drilled at the tip of the crack or slot.
The term recess is intended to refer below to a crack which has grown naturally, to a weakening, crack-directing notch as "predetermined breaking point" which permits crack propagation only in the prescribed direction and causes only a minimum leakage cross section on account of the small opening of a crack which has grown in the remaining wall thickness, or to a slot specifically made in a component.
A considerable leakage cross section, which is undesirable, for example, in fluid-flow machine construction, is disadvantageously produced by the boring out of the recess tip. For this reason and for strength reasons, a bore diameter which is too small to result in a lasting solution to the abovementioned problem is therefore often selected in practice.
On the basis of knowledge gained in the field of fracture mechanics, it is known that, by a suitable run-out of the crack tip, i.e. a suitable configuration of the recess termination, further growth of the crack or the recess can be inhibited or prevented, so that it is possible to continue to use and load the component.